JP2016020048A - Thermal transfer image receiving sheet, combination of thermal transfer image receiving sheet and thermal transfer sheet and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer image receiving sheet that can increase a print density, is excellent in releasability of a thermal transfer sheet and a thermal transfer image receiving sheet during heating, can suppress image blur of a printed matter during storage under high temperature and can afford good light fastness of the printed matter, to provide a combination of the thermal transfer image receiving sheet and a thermal transfer sheet and to provide an image forming method that forms an image using the combination of the thermal transfer image receiving sheet and the thermal transfer sheet.SOLUTION: In a thermal transfer image receiving sheet 1 having a dye receiving layer 3 on one surface of a base material sheet 2, the dye receiving layer 3 contains a polymer plasticizer including a constitutional unit derived from ethylene and a hindered amine-based photostabilizer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal transfer image receiving sheet, a combination of the thermal transfer image receiving sheet and the thermal transfer sheet, and an image forming method for forming an image on the thermal transfer image receiving sheet by combining the thermal transfer image receiving sheet and the thermal transfer sheet. .

  Conventionally, various thermal transfer recording methods are known. Among them, a thermal transfer sheet having a dye layer in which a dye for sublimation transfer is used as a recording material and this is supported on a base material such as a polyester film with a suitable binder. From the above, there are proposed methods for forming various full-color images by thermally transferring a sublimation dye onto a transfer material that can be dyed with a sublimation dye, for example, a thermal transfer image-receiving sheet having a dye-receiving layer formed on paper or a plastic film. Yes. In this case, as the heating means, the color dots having a large number of three or four colors adjusted by heating with the thermal head of the printer are transferred to the receiving layer of the thermal transfer image receiving sheet, and the multicolored color dots are transferred. To reproduce a full color image. The image formed in this way is very clear and excellent in transparency because the coloring material used is a dye, so the resulting image is excellent in the reproducibility and gradation of intermediate colors, It is possible to form a high-quality image similar to an image obtained by offset printing or gravure printing and comparable to a full-color photographic image.

  In the thermal transfer image-receiving sheet, the dye transfer sensitivity of the dye-receiving layer and the various durability and storage stability of the image formed by the thermal transfer depend greatly on the binder resin forming the dye-receiving layer. For example, the light resistance of the formed image largely depends on the composition structure of the receiving layer resin, and it is necessary to select an optimal resin composition. In addition, as a means to improve the transfer sensitivity of the dye, it is only necessary to improve the diffusibility of the dye during thermal transfer, and a method of using a resin having a low glass transition temperature as a receiving layer resin, or adding a plasticizer in the receiving layer There are ways to do this.

For example, Patent Document 1 describes that a dye receiving layer is made to contain a plasticizer containing an ethylene structure (EVA polymer plasticizer, Elvalloy 741P) to increase the printing density and fastness.
However, it has been found that when the above plasticizer containing an ethylene structure is added to the dye-receiving layer, bleeding is likely to occur in the thermal transfer image of the printed matter under high temperature storage.

JP-A-10-81075

  The present invention has been made in such a situation, the printing density can be increased, the releasability at the time of heating the thermal transfer sheet and the thermal transfer image receiving sheet is excellent, and the image of the printed matter under high temperature storage Thermal transfer image-receiving sheet capable of suppressing bleeding and further improving the light resistance of the printed material, a combination of the thermal transfer image-receiving sheet and the thermal transfer sheet, and an image forming method for forming an image using the combination of the thermal transfer image-receiving sheet and the thermal transfer sheet The purpose is to provide.

  The above object is achieved by the present invention described below. That is, the present invention relates to a thermal transfer image-receiving sheet provided with a dye-receiving layer on one side of a base sheet, wherein the dye-receiving layer is composed of a polymer plasticizer containing a structural unit derived from ethylene and a hindered amine light stabilizer. And a thermal transfer image-receiving sheet.

  The hindered amine light stabilizer has a melting point of 80 ° C. or higher.

  Also, a thermal transfer image-receiving sheet provided with a dye-receiving layer on one side of the base sheet, and a dye layer containing a dye and a binder resin are provided on one side of the base, and the other side of the base It is a combination with a thermal transfer sheet provided with a heat-resistant slip layer on the surface, and the dye-receiving layer of the thermal transfer image-receiving sheet contains a polymer plasticizer containing a structural unit derived from ethylene and a hindered amine light stabilizer And the dye layer of the thermal transfer sheet is provided on one side of the base material, or two or more types are repeatedly provided in the surface order, and at least one type of the dye layer is As the binder resin, a thermal transfer sheet and a thermal transfer image-receiving sheet comprising nitrocellulose within a range of 50% by mass to 100% by mass with respect to the total solid content of the binder resin It is a combination seen.

  Also, a thermal transfer image-receiving sheet provided with a dye-receiving layer on one side of the substrate sheet, a dye layer provided on one side of the substrate, and a heat-resistant slipping layer provided on the other side of the substrate The thermal transfer sheet is used in combination to form an image on the thermal transfer image-receiving sheet, wherein the dye-receiving layer of the thermal transfer image-receiving sheet includes a polymer plasticizer containing a structural unit derived from ethylene, And a hindered amine light stabilizer, and the dye layer of the thermal transfer sheet contains a dye and a binder resin, and is provided on one surface of the base material, or two or more kinds thereof. Are provided in plane order, and at least one of the dye layers contains nitrocellulose as the binder resin within a range of 50% by mass to 100% by mass with respect to the total solid content of the binder resin. It characterized the door, an image forming method.

  According to the present invention, the print density can be increased, the releasability at the time of heating between the thermal transfer sheet and the thermal transfer image receiving sheet is excellent, the image bleeding of the printed matter under high temperature storage can be suppressed, and the printed matter The light resistance is also improved.

It is a schematic sectional drawing which shows one embodiment of the thermal transfer image receiving sheet of this invention. It is a schematic sectional drawing which shows one embodiment of the combination of the thermal transfer image receiving sheet and thermal transfer sheet of this invention. It is a schematic sectional drawing which shows one embodiment of the thermal transfer sheet applied by this invention.

Next, an embodiment of the invention will be described in detail.
FIG. 1 shows one embodiment of the thermal transfer image receiving sheet of the present invention. The illustrated thermal transfer image-receiving sheet 1 has a configuration in which a dye-receiving layer 3 is provided on one side of a base sheet 2 and a back layer 4 is provided on the other side of the base sheet 2. The thermal transfer image receiving sheet of the present invention is not limited to the illustrated one, and the back layer is not essential and can be omitted. Moreover, you may form layers, such as an antistatic layer, a cushion layer, the intermediate | middle layer which added the white pigment, and the fluorescent whitening agent, and an easily bonding layer between a base material sheet and a dye receiving layer as needed. Further, a layer such as an antistatic layer may be formed on the back layer.

  FIG. 2 shows one embodiment of the combination of the thermal transfer image receiving sheet and the thermal transfer sheet of the present invention. The illustrated one is composed of a combination of a thermal transfer sheet 11 and a thermal transfer image-receiving sheet 1, and the thermal transfer sheet 11 is provided with a dye layer 13 on one surface of a substrate 12, and heat-resistant slipping property is provided on the other surface of the substrate 12. Layer 14 is provided. The thermal transfer image receiving sheet 1 has the same configuration as the thermal transfer image receiving sheet having the configuration shown in FIG. The thermal transfer sheet is not limited to the one shown in the figure, and an easy-adhesion layer or the like is provided between the base material and the dye layer as necessary, or a layer such as an antistatic layer is formed on the heat-resistant slipping layer. Also good.

  FIG. 3 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet used in the present invention. On one surface of the substrate 12, a Y (yellow) dye layer, an M (magenta) dye layer, and C ( Cyan) and a transferable protective layer 15 are repeatedly provided in the surface order.

Hereinafter, each configuration of the thermal transfer image receiving sheet of the present invention will be described.
(Base material sheet)
The substrate sheet 2 of the thermal transfer image receiving sheet is not particularly limited as long as it supports the dye receiving layer and other layers provided as necessary and can withstand the heating during the thermal transfer. For example, highly heat-resistant polyolefin such as polyethylene terephthalate and polyethylene naphthalate, polyester, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyamide, polymethylpentene and other plastic stretched or unstretched films, and these synthetic resins are white White opaque films formed by adding pigments and fillers can also be used. In addition, materials such as high-quality paper, coated paper, art paper, cast coated paper, and paperboard can also be used. Moreover, the composite film which laminated | stacked 2 or more types of these materials can also be used. Examples of typical laminates include cellulose fiber paper and synthetic paper or cellulose synthetic paper, plastic film, and synthetic paper. In the present invention, a commercially available base material can be used, for example, RC paper paper ( Mitsubishi Paper Industries, Ltd., trade name: STF-150) and the like are preferable.

  Although the thickness of a base material sheet can be suitably selected according to material so that the intensity | strength, heat resistance, etc. may become suitable, it is about 1 micrometer-300 micrometers normally, Preferably it is about 60 micrometers-200 micrometers.

(Dye-receiving layer)
The dye receiving layer 3 is for receiving the dye transferred from the thermal transfer sheet and maintaining the formed image. The dye-receiving layer in the present invention contains a polymer plasticizer containing a structural unit derived from ethylene and a hindered amine light stabilizer. Since this dye-receiving layer contains a polymer plasticizer containing a structural unit derived from ethylene, the print density is high and the light fastness of the printed matter is high. It has been found that the tendency to cause bleeding can be improved by adding a hindered amine light stabilizer. Further, by adding a hindered amine light stabilizer, the printing density and the light resistance performance could be further improved.

[Vinyl chloride resin]
A vinyl chloride resin or the like can be used as the binder resin of the dye receiving layer. The vinyl chloride resin is a polymer containing a structural unit derived from vinyl chloride. The vinyl chloride resin used in the present invention may consist only of vinyl chloride-derived structural units, or may be a copolymer of vinyl chloride and a copolymerizable monomer. In the present invention, a copolymer including a structural unit derived from vinyl chloride and a structural unit derived from another monomer is particularly preferable. For example, it is possible to adjust the releasability of the dye-receiving layer used in the present invention, the print density, etc. within a desired range by appropriately selecting and adjusting the type of other structural units and the copolymerization ratio. This is because it becomes easy.
In the present invention, since the vinyl chloride resin is selected as the binder resin of the dye receiving layer, the compatibility of the dye layer of the thermal transfer sheet used in combination with the nitrocellulose resin of the binder resin is poor, and the dye layer and the dye It seems that the effect of preventing heat fusion with the receiving layer is enhanced and an excellent print density can be obtained.

  The monomer copolymerized with vinyl chloride is not particularly limited as long as it can be copolymerized with vinyl chloride, vinyl alcohol derivatives such as vinyl acetate, vinyl alcohol, vinyl propionate; acrylic acid and methacrylic acid and their methyl, ethyl, propyl Acrylic acid and methacrylic acid esters such as butyl, 2-ethylhexyl ester; maleic acid derivatives such as maleic acid, diethyl maleate, dibutyl maleate, dioctyl maleate; vinyl ether derivatives such as methyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether Acrylonitrile, methacrylonitrile, styrene and the like are mentioned, and vinyl acetate is particularly preferable as the copolymer component.

  Accordingly, vinyl chloride-vinyl acetate copolymer is particularly preferably used as the vinyl chloride resin used in the dye-receiving layer. As the vinyl chloride-vinyl acetate copolymer, structural units derived from vinyl chloride and acetic acid are used. Not only in the case of a copolymer containing only vinyl-derived constitutional units, but also in a range not impeding the object of the present invention, constitutional units derived from acrylic acid and methacrylic acid derivatives, constitutional units derived from vinyl alcohol, constitutions derived from maleic acid It may include a unit or the like. Specific examples include vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylic acid ester copolymer, ethylene-vinyl chloride-acrylic acid ester copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, and the like. be able to. The component ratio of vinyl chloride and vinyl acetate in the copolymer may be any ratio, but the vinyl chloride component is preferably 50% by mass or more in the copolymer. Especially, it is preferable that the mass ratio of the component of vinyl chloride and vinyl acetate is 85 / 15-90 / 10. Moreover, it is preferable that components other than vinyl chloride and vinyl acetate mentioned above are 10 mass% or less.

  As a commercial product of vinyl chloride resin, for example, vinyl chloride-vinyl acetate copolymer is mentioned. Solvain C, sorbine CL, sorbine CH, sorbine CN, solvine C5, solvine M, solvine MF, solvine A, solvine A, solvine TA5R, Solvein TAO, Solvein MK6, Solvein TA2 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), ESREC A, ESREC C, ESREC M (all trade names, manufactured by Sekisui Chemical Co., Ltd.) ), Vinylite VAGH, Vinylite VYHH, Vinylite VMCH, Vinylite VYHD, Vinylite VYLF, Vinylite VYNS, Vinylite VMCC, Vinylite VMCA, Vinylite VAGD, Vinylite VERR, Vinylite VROH (all trade names, union car) Produced by id Co., Ltd.), DENKAVINYL 1000GKT, DENKAVINYL 1000L, DENKAVINYL 1000CK (all trade name, manufactured by Denki Kagaku Kogyo Co., Ltd.), and the like.

  The molecular weight of the vinyl chloride resin used in the present invention is not particularly limited as long as the releasability of the dye-receiving layer in the present invention is within a desired range, but the number average molecular weight is particularly high. , Preferably 30000 or more, more preferably 35000 or more. This is because by using a vinyl chloride resin having a number average molecular weight within such a range, the releasability of the dye-receiving layer used in the present invention can be further improved. In addition, the vinyl chloride resin used in the present invention may be only one type or two or more types. The content of the vinyl chloride resin is preferably 50 to 98% by mass (solid content conversion) of the entire dye receiving layer material, and more preferably 70 to 95% by mass. In the present invention, the “solid content” means all components other than the solvent.

[Polymer plasticizer containing structural units derived from ethylene]
The polymer plasticizer containing a structural unit derived from ethylene is a polymer containing a structural unit derived from ethylene. The polymer plasticizer penetrates between the polymer chains of the vinyl chloride resin and weakens the cohesive force to give plasticity, thereby improving the dye receiving ability and light resistance of the dye receiving layer of the present invention, Further, it has a function of increasing incompatibility with nitrocellulose, improving releasability from the dye layer of the thermal transfer sheet, and suppressing abnormal transfer.

  The polymer plasticizer containing a structural unit derived from ethylene preferably has a glass transition temperature of −30 ° C. or lower from the viewpoint of light resistance. On the other hand, from the viewpoint of releasability, the glass transition temperature is preferably −60 ° C. or higher. In addition, the glass transition temperature here is measured by the dynamic viscoelasticity method. The polymer plasticizer containing a structural unit derived from ethylene preferably has a melting point of 80 ° C. or less, and more preferably 75 ° C. or less, from the viewpoint of light resistance. On the other hand, from the viewpoint of releasability, the melting point is preferably 50 ° C. or higher, and more preferably 55 ° C. or higher. In addition, melting | fusing point here is measured based on JISK71211999.

  As the polymer plasticizer containing a structural unit derived from ethylene used in the present invention, among others, a terpolymer of ethylene, an unsaturated carboxylic acid alkyl ester and carbon monoxide, and ethylene, vinyl acetate and monoxide are used. One or more copolymers selected from the group consisting of terpolymers with carbon are preferred from the viewpoint of the function of suppressing abnormal transcription, and further, ethylene, an unsaturated carboxylic acid alkyl ester, and carbon monoxide. These terpolymers are preferred.

  In the terpolymer, the unsaturated carboxylic acid in the unsaturated carboxylic acid alkyl ester includes (meth) acrylic acid, ethacrylic acid, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, maleic acid, maleic anhydride And unsaturated carboxylic acids having 4 to 8 carbon atoms such as maleic acid monoester (monomethyl maleate, monoethyl maleate, etc.), maleic anhydride monoester (monomethyl maleate anhydride, monoethyl maleate anhydride, etc.). Among these, (meth) acrylic acid, maleic acid, maleic anhydride, maleic acid monoester, and maleic anhydride monoester are preferable, and (meth) acrylic acid is particularly preferable. In the present invention, (meth) acrylic acid represents acrylic acid or methacrylic acid.

  As the alkyl moiety in the unsaturated carboxylic acid alkyl ester, those having 1 to 12 carbon atoms are preferably used. More specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec- Examples of the alkyl group include butyl, t-butyl, 2-ethylhexyl, and isooctyl. In the present invention, the unsaturated carboxylic acid alkyl ester is a lower alkyl ester of (meth) acrylic acid such as methyl ester, ethyl ester, n-butyl ester or isobutyl ester of acrylic acid or methacrylic acid (carbon number of alkyl moiety). 1-6) are preferred.

  In the ternary copolymer, the copolymerization ratio is not particularly limited, but the content of the structural unit derived from the unsaturated carboxylic acid alkyl ester or vinyl acetate is 5 to 50 with respect to the total mass of the ternary copolymer. Preferably, the content of structural units derived from carbon monoxide is 3 to 20% by mass, and the content of structural units derived from unsaturated carboxylic acid alkyl ester or vinyl acetate is 20 to 20%. More preferably, the content is 40% by mass and the content of structural units derived from carbon monoxide is 5 to 15% by mass. The terpolymer is produced, for example, by a high-pressure radical copolymer known per se.

  As the polymer plasticizer containing a structural unit derived from ethylene, a commercially available product may be used. For example, as a commercial product of the terpolymer, Elvalloy series (trade name, Mitsui DuPont Polychemical Co., Ltd.) Manufactured). In addition, 1-20 mass% (solid content conversion) of the whole dye receiving layer material is preferable, and, as for content of the polymer plasticizer containing the structural unit derived from ethylene, 3-15 mass% is more preferable. In addition, the content ratio of the vinyl chloride resin and the polymer plasticizer containing a structural unit derived from ethylene is preferably 98: 2 to 80:20 from the viewpoint of abnormal transfer resistance and light resistance. Among these, 92: 8 to 85:15 is preferable from the viewpoint of increasing the transfer density.

[Hindered amine light stabilizer]
The hindered amine light stabilizer contained in the dye-receiving layer plays a role of efficiently capturing radical species and imparting light stability on the surface of a polymer material that is highly photooxidized caused by ultraviolet rays. it can.
The hindered amine light stabilizer is a compound in which all hydrogens on carbons at the 2nd and 6th positions of the piperidine ring are substituted with methyl groups. For example, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, 1,2,2,6,6-pentamethyl-4-piperidyl-tridecyl -1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ′, β'-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol condensate, bis (2,2,6,6-tetramethyl-4- Piperidyl) sebacate, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), amber Acid-bis (2,2,6,6 -Tetramethyl-4-piperidyl) ester, dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1, 1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2 , 2,6,6-tetramethyl-4-piperidyl) imino}], N, N′-bis (3-aminopropyl) ethylenediamine · 2,4-bis [N-butyl-N- (1,2,2 , 6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like.

  As a commercial item of the hindered amine light stabilizer having the structure as described above, trade names “ADK STAB LA-52”, “ADK STAB LA-57”, “ADK STAB LA-62”, and “Akastab LA-62” manufactured by Asahi Denka Kogyo Co., Ltd. ADK STAB LA-67, ADK STAB LA-63, ADK STAB LA-68LD, ADK STAB LA-77, ADK STAB LA-82 and ADK STAB LA-87 , “Tinuvin 770DF”, “Tinvin 780FF”, “Tinvin 144”, “Chimassorb 944FL”, “Chimassorb 944LD” and “Chimassorb 119FL”, trade names “SanolLS 770”, B.K. F. A product name “Googrite UV-3034” manufactured by Goodrich Co., Ltd. can be used.

  The hindered amine light stabilizer contained in the dye-receiving layer preferably has a melting point of 80 ° C. or higher. More preferably, the melting point is 100 ° C. or higher. When a hindered amine light stabilizer having a melting point of less than 80 ° C. is used, the releasability is lowered. The hindered amine light stabilizer preferably has a melting point of about 150 ° C. or lower. The blending amount of the hindered amine light stabilizer is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. If the amount of the hindered amine light stabilizer is less than 0.1 parts by mass, the effect of preventing discoloration (light resistance) during outdoor exposure tends to be insufficient, while if it exceeds 10 parts by mass, the protective layer is transferred. Inconveniences such as a decrease in printability and a decrease in print density are likely to occur.

[Silicone oil]
The dye-receiving layer of the thermal transfer image-receiving sheet of the present invention preferably contains silicone oil. As the silicone oil, those that can impart desired release properties to the dye receiving layer by being contained in the dye receiving layer are preferably used. Examples of the silicone oil used in the present invention include epoxy-modified silicone oil, alkyl-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, phenyl-modified silicone oil, polyether-modified silicone oil, vinyl-modified silicone oil, hydrogen Examples include modified silicone oils such as modified silicone oils. Of these, amino-modified silicone oils and epoxy-modified silicone oils are preferred, amino-modified silicone oils are more preferred, and diamine-modified silicone oils modified with diamines are preferred because of good peelability and high abnormal transfer resistance. Is more preferable. In addition, 0.1-10 mass% (solid content conversion) of the whole dye receiving layer material is preferable, and, as for the addition amount of silicone oil, 0.5-5 mass% is more preferable.

[Other ingredients]
In addition to the above, as an optional compound that can be added to the dye-receiving layer as long as the effect of the present invention is not hindered, for example, an antioxidant, an ultraviolet absorber, a filler, a pigment, an antistatic agent, a plasticizer, a heat A meltable substance etc. can be mentioned. Moreover, you may use together mold release agents other than a silicone oil in the range which does not prevent the effect of this invention. Examples of such a release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder, fluorine-based or phosphate-based surfactant, and the like. In addition, a binder resin other than the vinyl chloride resin may be used in combination as long as the effects of the present invention are not hindered. Examples of such a binder resin include acrylic resins, polyester resins, urethane resins, and the like. Even when a binder resin other than the vinyl chloride resin is used in combination, the vinyl chloride resin is the main component of the binder resin, that is, 50% by mass or more of the total of the binder resin, and further the total of the binder resin. It is preferably 70% by mass or more, and more preferably 90% by mass or more.

In forming the dye-receiving layer, the coating amount of the dye-receiving layer coating solution is not particularly limited, but preferably has the above-mentioned components and is 0.5 to 10 g / m ^{2 in} a dry state. .

The thermal transfer sheet 11 used in combination with the above thermal transfer image-receiving sheet is provided with a dye layer 13 containing a dye and a binder resin on one surface of a substrate 12, and a heat-resistant slipping layer on the other surface of the substrate 12. 14 is provided. Hereinafter, the configuration of the thermal transfer sheet will be described.
(Base material)
The substrate 12 used in the thermal transfer sheet 11 of the present invention is an essential component in the thermal transfer sheet of the present invention, and is provided to hold the dye layer 13 and the heat resistant slipping layer 14. The material of the substrate 12 is not particularly limited, but it is desirable that the substrate 12 has mechanical characteristics that can withstand the heat applied by the thermal head when transferring the dye of the dye layer 13 onto the thermal transfer image-receiving sheet and that does not hinder handling. Examples of such a substrate 12 include polyesters such as polyethylene terephthalate, polyarylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivatives, polyethylene, ethylene / vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polychlorinated. Vinyl, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyether sulfone, tetrafluoroethylene / perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene / hexa Various plastic films such as fluoropropylene, polychlorotrifluoroethylene, and polyvinylidene fluoride Mention may be made of Lum or sheet. Moreover, the thickness of the base material 12 can be appropriately set according to the material so that the strength and heat resistance are appropriate, and is generally about 2.5 μm to 100 μm, preferably 1 μm to 10 μm. .

(Dye layer)
The dye layer is mainly composed of a dye and a binder resin.
<Dye>
As the dye material contained in the dye layer 13, conventionally known dyes can be used, but those having good characteristics as a printing material, for example, having a sufficient coloring density, light, heat, temperature, etc. Those which do not discolor due to are preferred. Examples of the sublimable dye that can be used for the dye layer 13 of the sublimation type thermal transfer sheet include methine series such as diarylmethane dye, triarylmethane dye, thiazole dye, merocyanine dye, pyrazolone dye, pyrazolone methine, and pyridone methine. Dyes, indoaniline dyes, indonaphthol dyes, acetophenone azomethine, pyrazoloazomethine, pyrazolone azomethine, pyrazolotriazole azomethine, imidazole azomethine, imidazoazomethine, pyridone azomethine and other azomethine dyes, xanthene dyes, oxazine dyes, Cyanostyrene dyes such as dicyanostyrene and tricyanostyrene, thiazine dyes, azine dyes, acridine dyes, benzeneazo dyes, pyridoneazo, thiophenazo, thiazoleazo, i Azo dyes such as thiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, and disazo, spiropyran dyes, indolinospiropyran dyes, fluorane dyes, rhodamine lactam dyes, naphthoquinone dyes, anthraquinone dyes Quinophthalone dyes, aminopyrazole dyes, pyrazolotriazole dyes, styryl dyes such as dicyanostyryl and tricyanostyryl. Specifically, red dyes such as Disperse Red 60, Disperse Violet 26, CeresRed 7B, Samaron Red F3BS, yellow dyes such as Disperse Yellow 231, PTY-52, Macrolex Yellow 6G, Solvent Blue 63, Waxolin Blue AP-FW, Holon Brilliant Blue S-R, MS Blue 100, C.I. I. And blue dyes such as Solvent Blue 22.

<Binder resin>
Examples of the binder resin for the dye layer include polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, nitrocellulose, ethyl cellulose, methyl cellulose, cellulose acetate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, and polyvinyl acetate resin. And vinyl resins such as polyacrylamide resins, polyester resins and the like. In addition, these binder resins may be used independently and can also be used in combination of 2 or more type.

  The dye layer of the thermal transfer sheet used in combination with the thermal transfer image-receiving sheet of the present invention described above is provided on one side of the base of the thermal transfer sheet, or two or more types are repeatedly provided in the surface order. Is preferred. And it is preferable that at least 1 type of the dye layer contains nitrocellulose as a binder resin within the range of 50 mass% or more and 100 mass% or less with respect to the total solid content of the binder resin. The total solid content of the binder resin means the total solid content of the binder resin containing nitrocellulose in one kind of dye layer containing nitrocellulose. That is, when two or more types of dye layers are provided in the surface order, at least one type of dye layer is a dye layer containing nitrocellulose, and at least one other type is a dye layer containing no nitrocellulose. In the dye layer containing at least one nitrocellulose, the binder resin may contain nitrocellulose within a range of 50% by mass to 100% by mass with respect to the total solid content of the binder resin. That's fine.

  For example, in combination with a binder resin containing nitrocellulose within a range of 50% by mass or more and 100% by mass or less with respect to the total solid content of the binder resin for at least one dye which is difficult to achieve a high printing density As a result, the printing density can be improved even for dyes that are difficult to achieve high printing density. When at least one dye layer containing nitrocellulose is contained within a range of 50% by mass or more and 100% by mass or less with respect to the total solid content of the binder resin, the problem of abnormal transfer as described above is likely to occur. Therefore, it is preferable to combine with the specific thermal transfer image receiving sheet. However, even when nitrocellulose is contained in an amount that does not reach 50% by mass or more based on the total solid content of the binder resin, depending on the dye, a sufficient print density may be achieved, so in at least one kind of dye layer If the binder resin contains nitrocellulose within a range of 50% by mass to 100% by mass with respect to the total solid content of the binder resin, the binder resin in another dye layer containing nitrocellulose. Nitrocellulose may be contained in a range of less than 50% by mass with respect to the total solid content. Even in this case, in order to obtain the effect of containing nitrocellulose, it is preferable to contain 20% by mass or more of nitrocellulose with respect to the total solid content of the binder resin.

[Nitrocellulose]
Nitrocellulose as a binder resin has a high dye-holding power, so even if the mass ratio of dye to nitrocellulose (D / B ratio (dye / binder resin)) (hereinafter referred to as D / B ratio) increases, storage stability It is possible to satisfy the characteristics, and it is possible to prevent the occurrence of soiling, kick and back. Further, since the dye transfer efficiency is good, a high print density can be obtained even when the coating amount is reduced to increase the transfer efficiency.

  The viscosity of the nitrocellulose is not particularly limited, but when the dye layer 13 contains nitrocellulose having a viscosity of less than 1/16 according to JIS K-6703, the storage stability tends to decrease. On the other hand, when the dye layer 2 contains nitrocellulose having a viscosity of more than 120 according to JIS K-6703, there is a possibility that ink mist or the like may be generated when the dye layer 13 is formed.

In consideration of this point, the dye layer 13 preferably contains 1/16 or more and 120 or less nitrocellulose with a viscosity according to JIS K-6703, and contains 1/8 or more and 120 or less nitrocellulose. More preferably.
As the nitrocellulose having a viscosity within the above range, a commercially available product can be used as it is. Examples of the viscosity within the above range include, for example, the types and viscosity symbols specified in JIS K-6703 manufactured by Taihei Chemicals Co., Ltd., H1 / 16, H1 / 8, L1 / 8, H1 / 4. Examples include L1 / 4, H1 / 2, H1, H5, H20, H60, and H120. In addition, DHX3-5, DHX5-10, DHX8-13, DHX11-16, DHX30-50, DHX40-70, DHL25-45, DHL120-170, H20 (160-210) manufactured by Inabata Sangyo Co., Ltd. , DHM10-25, SL-1, DLX3-5, DLX5-8, DLX8-13, DLX30-50, etc. can also be used.

  Nitrocellulose preferably has a nitrogen content (nitrification degree) of 10% or more. In consideration of handling safety, the nitrogen content is preferably 12.3% or less. By containing nitrocellulose having a nitrogen content of 10% or more in the dye layer 13, further improvement in transfer efficiency is expected.

  In addition to the dye and the binder resin, the dye layer 13 may contain additives such as inorganic fine particles and organic fine particles within a range not impairing the suitability of the dye layer such as dye transfer property and printing density. Examples of the inorganic fine particles include carbon black, aluminum, and molybdenum disulfide. Examples of the organic fine particles include polyethylene wax. The dye layer 13 may contain other release agents within a range that does not hinder the gist of the present invention. Examples of other release agents include conventionally known silicones and phosphate esters.

  The method for forming the dye layer 13 is not particularly limited, and a dye, a binder resin, and additives as necessary, for example, a release agent or inorganic fine particles are added, and toluene, methyl ethyl ketone, isopropyl alcohol, ethanol, cyclohexanone, Apply a coating solution dissolved in an appropriate organic solvent such as DMF or dispersed in an organic solvent or water by means of gravure printing, die coating printing, bar coating printing, screen printing, or reverse roll coating printing using a gravure plate. And can be formed by drying.

Moreover, in this invention, it is preferable that the coating amount of the dye layer 13 shall be the range of 0.50 g / m < ² > or less at the time of drying. By making the coating amount of the dye layer 13 within this range, the dye transfer efficiency at the time of transfer can be improved, and the dye contained in the dye layer 13 can be transferred onto the thermal transfer image receiving sheet without waste, In addition, the storage stability requirement can be satisfied. If the coating amount of the dye layer 13 exceeds 0.50 g / m ² at the time of drying, the dye transfer efficiency may be lowered. The lower limit value of the dye layer 13 is not particularly limited, but when the coating amount of the dye layer is less than 0.13 g / m ² at the time of drying, the blending ratio of the sublimable dye to the nitrocellulose may be increased. In some cases, sufficient print density cannot be obtained. Therefore, considering this point, the coating amount of the dye layer is preferably 0.13 g / m ² or more 0.50 g / m ² or less at the time of drying.

  When the content of the dye contained in the dye layer 13 is small, a sufficient print density may not be obtained. Considering this point, in one kind of dye layer containing nitrocellulose within the range of 50% by mass or more and 100% by mass or less with respect to the total solid content of the binder resin, the dye contained in the binder resin and the binder resin The mass ratio (D / B ratio (dye / binder resin)) is preferably 1.8 or more from the viewpoint that a printed matter having a sufficient printing density can be obtained. In addition, when the D / B ratio is usually 1.8 or more, the conventionally known binder resin that has been used so far cannot retain the sublimable dye, but the total solid content of the binder resin In one type of dye layer containing nitrocellulose within the range of 50% by mass or more and 100% by mass or less, the D / B ratio is 1.8 or more because the dye layer 13 contains a predetermined amount of nitrocellulose. However, the dye can be retained sufficiently and is excellent in storage stability. Although there is no particular limitation on the preferable upper limit value of the D / B ratio, when the D / B ratio exceeds 3.5, the amount of the dye with respect to the binder resin is too large, and the binder cannot hold the dye, so that the storage stability is maintained. May decrease. Therefore, considering this point, the D / B ratio is preferably in the range of 1.8 or more and 3.5 or less, and more preferably in the range of 2.0 or more and 3.5 or less.

(Dye primer layer)
In the present invention, the dye primer layer 15 can be provided between the substrate and the dye layer. By providing the dye primer layer, the adhesion between the substrate and the dye layer can be improved, and the prevention of abnormal transfer of the dye layer to the thermal transfer image receiving sheet during thermal transfer can be enhanced.

  Examples of the resin constituting the dye primer layer include polyester resins, polyvinyl pyrrolidone resins, polyvinyl alcohol resins, hydroxyethyl cellulose, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylamides. Resins, polyamide resins, polyether resins, polystyrene resins, polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral, and the like.

  The dye primer layer can also be composed of colloidal inorganic pigment ultrafine particles. This not only prevents abnormal transfer of the dye layer to the thermal transfer image-receiving sheet during thermal transfer, but also prevents dye transfer from the dye layer to the dye primer layer during printing, and diffusion of the dye to the dye-receiving layer side of the thermal transfer image-receiving sheet Can be effectively performed, and there is an effect of increasing the print density.

  As the colloidal inorganic pigment ultrafine particles, conventionally known compounds can be used. For example, silica (colloidal silica), alumina or alumina hydrate (alumina sol, colloidal alumina, cationic aluminum oxide or its hydrate, suspect boehmite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, magnesium oxide, oxidation Examples include titanium. In particular, colloidal silica and alumina sol are preferably used. These colloidal inorganic pigment ultrafine particles have a primary average particle size of 100 nm or less, preferably 50 nm or less.

The dye primer layer uses the gravure coating method, roll coating method, screen printing method, and gravure plate for the primer layer coating solution prepared by dissolving or dispersing the above-exemplified resins and colloidal inorganic pigment ultrafine particles in an appropriate solvent. It can be formed by coating and drying by a conventionally known forming means such as a reverse roll coating method. The coating amount of the primer layer coating solution is preferably about 0.02 to 1.0 g / m ² when dried.

(Heat resistant slipping layer)
The heat-resistant slipping layer 14 can be provided for the main purpose of preventing thermal fusion between a heating device such as a thermal head and the base material 12 and running smoothly. Examples of the resin used for the heat resistant slipping layer include cellulose resins such as ethyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, and nitrocellulose, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, and polyvinyl. Vinyl resins such as acetal and polyvinyl pyrrolidone, acrylic resins such as polymethyl methacrylate, polyethyl acrylate, polyacrylamide, and acrylonitrile-styrene copolymers, polyamide resins, polyvinyl toluene resins, coumarone indene resins, polyester resins A simple substance or a mixture of natural or synthetic resins such as polyurethane resin, silicone-modified or fluorine-modified urethane is used. In order to further improve the heat resistance of the heat resistant slipping layer, among the above resins, a resin having a hydroxyl group reactive group is used, and a polyisocyanate or the like is used in combination as a crosslinking agent to form a crosslinked resin layer. It is preferable.

Further, in order to impart slidability with the thermal head, a solid or liquid release agent or lubricant may be added to the heat-resistant slip layer to provide heat-resistant slip. Examples of the release agent or lubricant include various waxes such as polyethylene wax and paraffin wax, higher aliphatic alcohols, organopolysiloxanes, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants. Activators, fluorosurfactants, organic carboxylic acids and derivatives thereof, fluororesins, silicone resins, fine particles of inorganic compounds such as talc, silica, and the like can be used. The amount of the release agent or lubricant contained in the heat resistant slipping layer is 5 to 50% by mass, preferably about 10 to 30% by mass. The thickness of such a heat-resistant slip layer, a conventionally known means, coating, drying, dry with 0.1 to 10 g / m ² approximately, preferably 0.5 to 5 g / m ² approximately be able to.

(Transferable protective layer)
In the thermal transfer sheet used in the present invention, the dye layer and the transferable protective layer 18 described above can also be provided in the surface order (for example, FIG. 3 shown in the examples described later).
The transferable protective layer 18 may have a multilayer structure or a single layer structure. In the case of a multi-layer structure, in addition to the main protective layer 16 as a main component for imparting various durability to the image, transferability protection is provided to enhance the adhesion between the transferable protection layer and the image receiving surface of the printed material. The adhesion layer 17 arrange | positioned on the outermost surface of a layer, an auxiliary | assistant protective layer, the layer for adding functions other than the function of a protective layer main body, etc. may be contained. The order of the main protective layer and the other layers is arbitrary, but in general, other layers are provided between the adhesive layer 17 and the main protective layer 16 so that the main protective layer 16 becomes the outermost surface layer of the image receiving surface after transfer. It is preferable to arrange the layers.

  The main protective layer or the single-layered transferable protective layer constituting the multi-layered transferable protective layer can be formed of various resins conventionally known as protective layer forming resins. Examples of the resin for forming the protective layer include polyester resins, polystyrene resins, acrylic resins, polyurethane resins, acrylic urethane resins, resins obtained by silicone-modifying these resins, mixtures of these resins, ionizing radiation curable resins, An ultraviolet blocking resin can be exemplified. The protective layer containing the ionizing radiation curable resin is particularly excellent in plasticizer resistance and scratch resistance. As the ionizing radiation curable resin, known ones can be used. For example, a radical polymerizable polymer or oligomer is crosslinked and cured by ionizing radiation irradiation, and a photopolymerization initiator is added if necessary, and an electron beam Those obtained by polymerization and crosslinking with ultraviolet rays can be used.

  The main purpose of the protective layer containing the ultraviolet blocking resin is to impart light resistance to the printed material. As the ultraviolet blocking resin, for example, a resin obtained by reacting and bonding a reactive ultraviolet absorber with a thermoplastic resin or the above ionizing radiation curable resin can be used. More specifically, addition-polymerizable double-reactive organic UV absorbers such as salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, nickel chelates, hindered amines, etc. Examples thereof include those in which a reactive group such as a bond (for example, a vinyl group, an acryloyl group, a methacryloyl group), an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, or an isocyanate group is introduced.

The main protective layer provided in the single-layered transferable protective layer or the multi-layered transferable protective layer usually has a thickness of about 0.5 to 10 μm, although it depends on the type of protective layer-forming resin. Preferably there is.
An adhesive layer may be formed on the outermost surface of the transferable protective layer. The adhesive layer should be formed of a resin having good adhesiveness when heated, such as acrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin, polyester resin, polyamide resin. Can do. The thickness of the adhesive layer is usually about 0.1 to 5 g / m ² at the time of drying by coating and drying by a conventionally known means. Further, the dye primer layer may be formed at an arbitrary position in the multilayer structure of the transferable protective layer, or the dye primer layer may not be formed.

(Image forming method)
The image forming method of the present invention comprises a thermal transfer image-receiving sheet provided with a dye-receiving layer on one side of a substrate sheet, a dye layer provided on one side of the substrate, and heat-resistant on the other side of the substrate. A method of forming an image on the thermal transfer image-receiving sheet using a combination of a thermal transfer sheet provided with a slipping layer, wherein the dye-receiving layer of the thermal transfer image-receiving sheet comprises A molecular plasticizer and a hindered amine light stabilizer, and the dye layer of the thermal transfer sheet contains a dye and a binder resin, and is provided on one side of the substrate, Or at least one of the dye layers is a nitro resin within a range of 50% by mass to 100% by mass with respect to the total solid content of the binder resin. cellulose It is characterized in that it contains.

  That is, in the image forming method of the present invention, the dye receiving layer containing the polymer plasticizer containing the structural unit derived from ethylene described in the combination of the present invention and the hindered amine light stabilizer is provided on one of the base sheets. The thermal transfer image-receiving sheet 1 provided on the surface and the dye layer containing the dye and the binder resin are provided on one side of the base material, or two or more types are repeatedly provided in the surface order. At least one of the dye layers is combined with the thermal transfer sheet 11 having a feature of containing nitrocellulose within a range of 50% by mass or more and 100% by mass or less with respect to the total solid content of the binder resin as the binder resin. This is characterized in that an image is formed. The dye layer 13 of the thermal transfer sheet 11 described above and the dye receiving layer 3 of the thermal transfer image receiving sheet 1 are overlapped, and heat is applied from the back side (heat resistant slipping layer side) of the thermal transfer sheet 11 by a thermal head. Image formation is performed by transferring the dye contained in the dye layer 13 to the dye receiving layer 3.

  The thermal transfer sheet mainly composed of nitrocellulose as the binder resin for the dye layer has high dye transfer efficiency and improves storage stability even when the ratio of the dye to the binder resin is increased in order to improve the printing density. Although it is excellent, the releasability of the thermal transfer image-receiving sheet from the dye-receiving layer deteriorates, causing thermal fusion between the dye layer and the dye-receiving layer, or when separating the dye layer from the dye-receiving layer. In many cases, peeling marks are generated, and problems such as thermal fusion and deterioration of the quality of the printed matter due to the peeling marks are likely to occur. As described above, in the image forming method of the present invention, for such a thermal transfer sheet, the dye-receiving layer includes a vinyl chloride resin, a polymer plasticizer containing a structural unit derived from ethylene, and a hindered amine light. By combining a thermal transfer image-receiving sheet containing a stabilizer and silicone oil, the abnormal transfer as described above is suppressed to prevent deterioration of the quality of the printed matter such as thermal fusion and peeling marks, and printing. The light resistance of the object can be improved, and further, the image bleeding of the printed object under high temperature storage can be suppressed. The thermal transfer image receiving sheet and thermal transfer sheet used in the image forming method of the present invention are as described in the combination of the present invention, and detailed description thereof is omitted here.

  According to the image forming method of the present invention, since the specific thermal transfer image receiving sheet and the specific thermal transfer sheet described above are used, high density printing is performed even in high speed printing at a printing speed of 0.5 to 1.5 msec / line. Can be realized. In the image forming method according to the present invention, the resolution can be set to 300 dpi, for example.

Next, the present invention will be described more specifically with reference to examples and comparative examples. “Part” in the text is based on mass unless otherwise specified.
Example 1
(1) Preparation of thermal transfer sheet A polyethylene terephthalate film having a thickness of 5 μm was used as the substrate 12, and a coating solution for a heat-resistant slipping layer having the following composition was applied thereon so as to be 0.5 g / m ² when dried. The heat-resistant slip layer 14 was formed by drying. Next, a coating solution for the main protective layer of the transferable protective layer having the following composition is applied to a part of the surface of the substrate 12 opposite to the side on which the heat-resistant slip layer 14 is provided. The main protective layer 16 for the transferable protective layer was formed in a region where the transferable protective layer 18 was formed by coating and drying so as to be 0 g / m ² . Next, a dye primer layer coating solution having the following composition is applied to the entire surface of the substrate 12 opposite to the side on which the heat-resistant slip layer 14 is provided so as to be 0.1 g / m ² when dried. And dried to form the dye primer layer 15. Next, a yellow dye layer coating liquid 1, a magenta dye layer coating liquid 1, a cyan dye layer coating liquid 1 having the following composition and an adhesive layer for a transferable protective layer are formed on the primer layer 15. The coating solution and each dye layer 13 are repeated in this order in order of 0.5 g / m ² when dried and the dry coating amount of the adhesive layer 17 for transferable protective layer is 1.0 g / m ^2. Coating and drying to form a yellow dye layer (Y), a magenta dye layer (M), and a cyan dye layer (C), and further, a main protective layer 16 for the transferable protective layer, a dye primer layer 15, and a transferable protective layer. A thermal transfer sheet used in Example 1 as shown in FIG. 3 was obtained by forming the transferable protective layer 18 on which the adhesive layer 17 for layers was laminated.

<Coating fluid for heat resistant slipping layer>
Polyvinyl acetal resin (ESREC KS-1 manufactured by Sekisui Chemical Co., Ltd.) 60.8 parts Polyisocyanate (Bernock D750 manufactured by Dainippon Ink & Chemicals, Inc.) 4.2 parts Zinc stearyl phosphate (LBT-1830) Purified Sakai Chemical Industry Co., Ltd.) 10 parts ・ Zinc stearate (SZ-PF Sakai Chemical Industry Co., Ltd.) 10 parts ・ Polyethylene wax (Polywax 3000 Toyo Petrolite Co., Ltd.) 10 parts ・ Methyl ethyl ketone 200 parts・ Toluene 100 parts

<Coating liquid for main protective layer for transferable protective layer>
・ 20 parts acrylic resin (Dianar BR87, manufactured by Mitsubishi Rayon Co., Ltd.)
・ Methyl ethyl ketone 40 parts ・ Toluene 40 parts

<Dye primer layer coating solution>
・ Alumina sol (solid content 10%, manufactured by Nissan Chemical Industries, Ltd.) 30 parts ・ Polyvinylpyrrolidone resin (manufactured by K-90 ISP) 3 parts ・ Water 50 parts ・ Isopropyl alcohol 17 parts

<Yellow dye layer coating solution 1>
-Disperse dye (dye represented by the following chemical formula (A)) 2.5 parts-Disperse dye (dye represented by the following chemical formula (B)) 2.5 parts-Polyvinylacetoacetal resin (KS-5 Sekisui Chemical Co., Ltd.) )) 2.8 parts polyethylene wax (ACumist 1204 Honeywell)
0.1 part ・ Methyl ethyl ketone 45.0 parts ・ Toluene 45.0 parts

<Coating liquid 1 for magenta dye layer>
-Disperse dye (dye represented by the following chemical formula (C)) 3.5 parts-Nitrocellulose resin (solid content 70% H40 equivalent, nitrification degree 11.7-12.2%)
(DHM10-25 Inabata Sangyo Co., Ltd.) 2.0 parts (solid content 1.4 parts)
-Polyethylene wax (ACumist 1204 Honeywell)
0.1 part ・ Methyl ethyl ketone 45.0 parts ・ Toluene 45.0 parts

<Cyan dye layer coating solution 1>
・ Disperse dye (dye represented by the following chemical formula (D)) 2.5 parts ・ Disperse dye (dye represented by the following chemical formula (E)) 2.5 parts ・ Polyvinylacetoacetal resin (KS-5 Sekisui Chemical Co., Ltd.) )) 4.5 parts ・ Polyethylene wax 0.1 part ・ Methyl ethyl ketone 45.0 parts ・ Toluene 45.0 parts

<Coating liquid for adhesive layer for transferable protective layer>
・ 20 parts of polyester resin (Byron 200 manufactured by Toyobo Co., Ltd.)
UV absorber copolymer resin 10 parts (UVA-635L manufactured by BASF)
・ Methyl ethyl ketone / toluene (mass ratio 1: 1) 80 parts

(2) Production of thermal transfer image-receiving sheet As a base sheet, a porous polyethylene film (Toyopearl SS P4255 Toyobo Co., Ltd.) was used as an insulating layer on RC base paper (155 g / m ² , thickness 151 μm) (Mitsubishi Paper Co., Ltd.). Co., Ltd. (thickness 35 μm) was dry-laminated using a urethane adhesive (coating amount 5 g / m ² ) to obtain a support in which a base sheet and a heat insulating layer were laminated. Next, an intermediate layer was formed by coating an intermediate layer coating solution having the following composition on the support on the heat insulating layer side so as to have a thickness of 1.0 g / m ² . Next, a dye receiving layer coating solution 1 having the following composition is applied on the intermediate layer so as to have a thickness of 2.5 g / m ² to form a dye receiving layer, and a base sheet / heat insulating layer / intermediate layer / A thermal transfer image receiving sheet of Example 1 in which the dye receiving layers were laminated in this order was obtained.

<Intermediate layer coating solution>
・ Polyester resin (Polyester WR-905, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 50 parts ・ Titanium oxide (TCA888, manufactured by Tochem Products Co., Ltd.) 20 parts ・ Fluorescent whitening agent (Ubitex BAC Ciba Specialty Chemicals ( Made by Co., Ltd.)
1.2 parts water / isopropyl alcohol = 1/1 (mass ratio) 28.8 parts

<Dye-receiving layer coating solution 1>
・ 95% vinyl chloride resin (vinyl chloride-vinyl acetate copolymer resin, sorbine C Nissin Chemical Industry Co., Ltd.) ・ Polymer plasticizer containing ethylene-derived structural units (Elvalloy HP661, Mitsui, DuPont Polychemical Co., Ltd.) , Glass transition temperature -42 ° C., melting point 60 ° C.) 5 parts amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part hindered amine light stabilizer (Tinuvin 144 manufactured by Ciba Geigy Japan, number average molecular weight 685, melting point 146 to 150 ° C.) 5 parts / Methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

(Example 2)
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1, except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with the dye-receiving layer coating solution 2 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 2>
・ 95% vinyl chloride resin (vinyl chloride-vinyl acetate copolymer resin, sorbine C Nissin Chemical Industry Co., Ltd.) ・ Polymer plasticizer containing ethylene-derived structural units (Elvalloy HP661, Mitsui, DuPont Polychemical Co., Ltd.) , Glass transition temperature -42 ° C., melting point 60 ° C.) 5 parts amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part hindered amine light stabilizer (Chimassorb944 FDL, manufactured by Ciba Geigy, Japan), number average molecular weight 2000-3100 , Melting point: 100 to 135 ° C.) 5 parts ・ Methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

(Example 3)
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with the dye-receiving layer coating solution 3 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 3>
・ 95% vinyl chloride resin (vinyl chloride-vinyl acetate copolymer resin, sorbine C Nissin Chemical Industry Co., Ltd.) ・ Polymer plasticizer containing ethylene-derived structural units (Elvalloy HP661, Mitsui, DuPont Polychemical Co., Ltd.) 5 parts amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part hindered amine light stabilizer (ADK STAB LA-63P, manufactured by Asahi Denka Kogyo Co., Ltd.) , Number average molecular weight about 2000, melting point 85-105 ° C.) 5 parts / methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

Example 4
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1, except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with the dye-receiving layer coating solution 4 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 4>
・ 95% vinyl chloride resin (vinyl chloride-vinyl acetate copolymer resin, sorbine C Nissin Chemical Industry Co., Ltd.) ・ Polymer plasticizer containing ethylene-derived structural units (Elvalloy HP661, Mitsui, DuPont Polychemical Co., Ltd.) , Glass transition temperature -42 ° C, melting point 60 ° C) 5 parts amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part hindered amine light stabilizer (Chimassorb2020FDL, manufactured by Ciba Geigy, Japan), number average molecular weight 2600-3400 , Melting point 130-136 ° C.) 5 parts / methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

(Example 5)
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1, except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with the dye-receiving layer coating solution 5 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 5>
・ 95% vinyl chloride resin (vinyl chloride-vinyl acetate copolymer resin, sorbine C Nissin Chemical Industry Co., Ltd.) ・ Polymer plasticizer containing ethylene-derived structural units (Elvalloy HP661, Mitsui, DuPont Polychemical Co., Ltd.) , Glass transition temperature -42 ° C., melting point 60 ° C.) 5 parts amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part hindered amine light stabilizer (Tinuvin 770DF Nippon Ciba Geigy, number average molecular weight 481, melting point 81-85 ° C) 5 parts · Methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

(Comparative Example 1)
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1, except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with the dye-receiving layer coating solution 6 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 6>
・ Vinyl chloride resin (Vinyl chloride-vinyl acetate copolymer resin Solvein C Nissin Chemical Industry Co., Ltd.) 100 parts ・ Amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part ・ Methyl ethyl ketone (MEK) -500 parts of toluene mixed solvent (mass ratio 1: 1)

(Comparative Example 2)
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with the dye-receiving layer coating solution 7 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 7>
・ Vinyl chloride resin (Vinyl chloride-vinyl acetate copolymer resin Solvein C Nissin Chemical Industry Co., Ltd.) 100 parts ・ Amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part ・ Hindered amine light stability Agent (Tinuvin 144, manufactured by Ciba Geigy, Japan, number average molecular weight 685, melting point 146 to 150 ° C.) 5 parts, methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

(Comparative Example 3)
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1, except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with a dye-receiving layer coating solution 8 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 8>
・ Vinyl chloride resin (vinyl chloride-vinyl acetate copolymer resin Solvain C Nissin Chemical Industry Co., Ltd.) 90 parts ・ Polymer plasticizer containing ethylene-derived structural unit (Elvalloy HP661 Mitsui DuPont Polychemical Co., Ltd.) , Glass transition temperature -42 ° C., melting point 60 ° C.) 10 parts ・ Amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part ・ Methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

(Comparative Example 4)
A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer coating solution 1 in the thermal transfer image-receiving sheet prepared in Example 1 was replaced with the dye-receiving layer coating solution 9 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 9>
・ 95% vinyl chloride resin (vinyl chloride-vinyl acetate copolymer resin, sorbine C Nissin Chemical Industry Co., Ltd.) ・ Polymer plasticizer containing ethylene-derived structural units (Elvalloy HP661, Mitsui, DuPont Polychemical Co., Ltd.) , Glass transition temperature -42 ° C., melting point 60 ° C.) 5 parts amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part UV absorber (Tinuvin 111FDL, manufactured by Ciba Geigy, Japan) 5 parts methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

(Comparative Example 5)
A thermal transfer image receiving sheet was prepared in the same manner as in Example 1 except that the dye receiving layer coating solution 1 in the thermal transfer image receiving sheet prepared in Example 1 was replaced with the dye receiving layer coating solution 10 having the following composition. The thermal transfer sheet is the same as in Example 1, and there is no change.
<Dye-receiving layer coating solution 10>
・ Vinyl chloride resin (Vinyl chloride-vinyl acetate copolymer resin Solvein C Nissin Chemical Industry Co., Ltd.) 100 parts ・ Amino-modified silicone oil (KF-857 Shin-Etsu Chemical Co., Ltd.) 1 part ・ UV absorber ( Tinuvin 111FDL, manufactured by Nippon Ciba-Geigy Co., Ltd., HALS blend product) 10 parts ・ Methyl ethyl ketone (MEK) -toluene mixed solvent (mass ratio 1: 1) 500 parts

The thermal transfer image receiving sheets and thermal transfer sheets prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were combined and evaluated as follows. The results are shown in Table 1.
(1) Print density Using the above-prepared thermal transfer image-receiving sheet and the thermal transfer sheet, an RGB value of 15 * n (n = n) is obtained using a sublimation thermal transfer printer (Citizen Systems Co., Ltd., model: CW-02). 0 to 17) gray 18 gradation gradation images were printed. The optical reflection density was measured by an optical densitometer (spectrolino manufactured by Gretag Macbeth Co.), the density of the portion (ODmax) to which the maximum energy was applied was measured, and the print density was evaluated based on the following evaluation criteria. .
(Evaluation of printing density)
A: The maximum density is 2.0 or more, and the transfer sensitivity is very high.
○: The highest density is 1.8 or more, and the transfer sensitivity is high.
Δ: The maximum density is 1.6 or more and less than 1.8, and the transfer sensitivity is slightly low.
X: The maximum density is less than 1.6, and the transfer sensitivity is low.

(2) Releasability Magenta dye of the thermal transfer sheet corresponding to the dye receiving layer of the thermal transfer image receiving sheet prepared above with a test printer (thermal head resolution: 300 dpi, feed rate: 2.0 mmsec / Line, head voltage 21 V). The thermal transfer image-receiving sheet that has been solidly printed with the layer and is in contact with the thermal transfer sheet is peeled off under the condition of HEIDON SURFACE PROPERTY TESTER TYPE: 14RD at a pulling speed of 200 mm / min to evaluate the releasability of the thermal transfer sheet to the thermal transfer image-receiving sheet. did. The evaluation criteria are as follows.
(Double-circle): There is no heat sealing | fusion and peeling is very light.
◯: No heat fusion and light peeling
Δ: There is no heat fusion, but peeling is a little heavy.

(3) Protective layer transferability Each corresponding protective layer was transferred and formed on the gradation image formed when the above-mentioned printing density was examined. For the printed matter having the gradation image, the transferable protective layer of each of the corresponding thermal transfer sheets in Examples and Comparative Examples is overlapped with the adhesive layer surface of the transferable protective layer and the image receiving surface of the printed matter facing each other. A protective layer was transferred and formed on the entire printing screen with a thermal head under the following printing conditions.

(Protective layer transfer conditions)
-Thermal head-Heating element average resistance: 5300 (Ω)
・ Print density in the main scanning direction: 300 dpi
-Sub-scanning direction printing density: 300 dpi
Applied power: 0.10 (w / dot)
1 line cycle: 2 (msec.)
・ Printing start temperature: 25 (℃)
Gradation control method: Using a multi-pulse test printer that can vary the number of divided pulses from 0 to 255 in one line period and having a pulse length obtained by equally dividing one line period into 256. The duty ratio was fixed to 90%, and the gradation was fixed to 256 for printing.

When the protective layer was transferred, the protective layer transferability was evaluated according to the following criteria.
A: The protective layer does not transfer normally to the thermal transfer image-receiving sheet, there is no fusion with the substrate side of the protective layer, and the surface of the protective layer to which the printed material is transferred is not roughened. The surface of the protective layer was smooth.
A: The protective layer was not fused to the substrate side of the protective layer, the protective layer was normally transferred to the thermal transfer image-receiving sheet, and the surface of the protective layer to which the print was transferred was smooth.
(Triangle | delta): Although a protective layer does not melt | fuse with the base material side, the protective layer surface to which the printed matter was transferred is slightly roughened. (Observation with the naked eye)

(4) Image blur resistance under high temperature storage Using a print having the above gradation image and having a protective layer transferred onto the image, the print was stored in an atmosphere at 60 ° C. for 1 week. The surface state after storage was visually observed. The image blur resistance was evaluated according to the following criteria.
A: No blur is observed in the gradation image.
○: No blur is observed in the gradation image.
X: Bleeding is observed in the gradation image.

(5) Light resistance Using a printed matter having the above gradation image and having a protective layer transferred on the image, the light resistance was evaluated by irradiating with a lamp under the following conditions.
・ Irradiation tester: Ci35 manufactured by Atlas
・ Light source: Xenon lamp ・ Filter: Inside = IR filter Outside = soda lime glass ・ Black panel temperature: 45 (℃)
Irradiation intensity: measured value at 1.2 (W / m ² ) -420 (nm) Irradiation energy: integrated value at 400 (kJ / m ² ) -420 (nm)

  The change in the optical reflection density before and after irradiation under the above light resistance conditions was measured with an optical densitometer (spectrolino manufactured by Gretag Macbeth Co., Ltd.). The light resistance was calculated according to the following evaluation criteria based on this residual ratio.

(Evaluation criteria for light resistance)
Residual rate (%) = (optical reflection density after irradiation / optical reflection density before irradiation) × 100
Evaluation criteria A: The residual ratio is 90% or more, and the light resistance is very good.
○: Residual rate is 80% or more and less than 90%, and light resistance is good.
X: The residual rate is 60% to 70%, and the light resistance is inferior.

Table 1 below shows the evaluation results of the print density, releasability, protective layer transferability, image bleeding resistance under high temperature storage, and light resistance of the above-mentioned prints.

  As shown in the above results, according to the thermal transfer image receiving sheets of Examples 1 to 5, and the combination of the thermal transfer sheet and the thermal transfer image receiving sheet, the print density of the printed material is high, and the thermal transfer sheet and the thermal transfer image receiving sheet are heated. The releasability of the printed matter was excellent, the transferability of the protective layer in the printed matter was excellent, the image bleeding of the printed matter under high temperature storage could be suppressed, and the light resistance of the printed matter was also good.

On the other hand, according to the thermal transfer image-receiving sheet of Comparative Example 1, the evaluation of the print density and the light resistance of the printed matter was a failure result, and the evaluation of the releasability was not good. According to the thermal transfer image-receiving sheet of Comparative Example 2, the evaluation of the print density of the printed matter was a result of the failure, and the evaluation of the releasability was not good.
According to the thermal transfer image receiving sheets of Comparative Examples 3 and 4, the evaluation of image bleeding resistance under high temperature storage was poor. Further, according to the thermal transfer image receiving sheet of Comparative Example 4, the evaluation of releasability was not good.
According to the thermal transfer image receiving sheet of Comparative Example 5, the evaluation of the print density of the printed matter and the image bleeding resistance under high temperature storage was poor.

DESCRIPTION OF SYMBOLS 1 Thermal transfer image receiving sheet 2 Base material sheet 3 Dye receiving layer 4 Back surface layer 10 Combination of thermal transfer image receiving sheet and thermal transfer sheet 11 Thermal transfer sheet 12 Base material 13 Dye layer 14 Heat resistant slipping layer 15 Dye primer layer 16 Main protection for transferable protective layer Layer 17 Adhesive layer for transferable protective layer 18 Transferable protective layer

Claims (4)

  In the thermal transfer image-receiving sheet provided with a dye-receiving layer on one surface of the base sheet, the dye-receiving layer contains a polymer plasticizer containing a structural unit derived from ethylene and a hindered amine light stabilizer. Thermal transfer image receiving sheet characterized by   The thermal transfer image-receiving sheet according to claim 1, wherein the hindered amine light stabilizer has a melting point of 80 ° C. or higher. A thermal transfer image-receiving sheet provided with a dye-receiving layer on one side of the base sheet;
A combination with a thermal transfer sheet in which a dye layer containing a dye and a binder resin is provided on one surface of the substrate and a heat-resistant slipping layer is provided on the other surface of the substrate,
The dye-receiving layer of the thermal transfer image-receiving sheet contains a polymer plasticizer containing a structural unit derived from ethylene, and a hindered amine light stabilizer,
One type of the dye layer of the thermal transfer sheet is provided on one surface of the base material, or two or more types are repeatedly provided in the surface order,
At least one of the dye layers contains, as the binder resin, nitrocellulose within a range of 50% by mass or more and 100% by mass or less with respect to the total solid content of the binder resin; Combination with thermal transfer image receiving sheet. A thermal transfer image-receiving sheet provided with a dye-receiving layer on one side of the base sheet;
A thermal transfer sheet provided with a dye layer on one surface of the substrate and a heat-resistant slipping layer on the other surface of the substrate;
An image forming method for forming an image on the thermal transfer image-receiving sheet by using in combination,
The dye-receiving layer of the thermal transfer image-receiving sheet contains a polymer plasticizer containing a structural unit derived from ethylene, and a hindered amine light stabilizer,
The dye layer of the thermal transfer sheet contains a dye and a binder resin, and is provided on one side of the base material, or two or more types are provided in the surface order,
At least one of the dye layers contains nitrocellulose as the binder resin in a range of 50% by mass to 100% by mass with respect to the total solid content of the binder resin. .

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